A common way to diagnose interconnect defects (e.g., shorts and opens) in circuit assemblies (e.g., printed circuit boards, Multi-Chip Modules, and Silicon-in-Package devices) is via Boundary-Scan testing. A standard for Boundary-Scan testing is defined in IEEE Standard 1149.1.
As the electronics industry has moved forward with the implementation of AC coupled networks, IEEE Std. 1149.1 has become out-of-date. This is because IEEE Std. 1149.1 was drafted at a time when DC coupled networks were the norm. In an AC coupled network, for example, series capacitors are used to block DC current flow along a signal path, thereby allowing only AC signals to pass. A standard that defines how to apply Boundary-Scan techniques to AC networks is therefore needed. To this end, work is underway on IEEE Std. P1149.6—a draft standard that addresses Boundary-Scan testing of circuit assemblies comprising AC coupled networks.